1. Technical Field
The present invention relates to a content distribution technology, and more particularly to a content distribution system, a content distribution server, a content distribution method, a software program, and a storage medium storing the software program to convert content to a format suitable for a client terminal.
2. Description of the Background Art
With the spread of the Internet and multimedia technology, information can now be transmitted various ways, including simple text data exchange using e-mail, uploading of multi-media content composed of audio/sound, moving images, and still image via a network, and downloading of multi-media content via the network for viewing and listening.
However, different users downloading content typically have different client terminals. In view of this difference in client terminal environments, when content is to be used at each client terminal via a network, the format of the content may need to be converted for each client terminal. For example, a format conversion server on a network converts the format of the content to one that is suitable for the client terminal in view of the format of the client terminal.
JP-2002-342218-A discloses a system using a format conversion server disposed on a network, in which the format conversion server converts the format of content suitable for a client terminal in view of the format of the client terminal such as displayable resolution level, types of colors, and frequency range playable by a speaker. The format conversion server provides the format-converted content to the client terminal via the network. The system includes a client terminal, a server to accumulate content (content accumulation server), and a server to convert content into a format usable at each client terminal (format conversion server) connected via a network. The format conversion server refers to a profile specifying the replay capability and display capability for content at each client terminal, wherein the profile is prepared at the concerned client terminal, to determine a format suitable for the concerned client terminal. After converting the format of the content received from the content accumulation server, the format conversion server transmits the format-converted content to a content providing unit, from which the format-converted content is transmitted to the concerned client terminal.
Further, JP-2010-061212-A discloses a data distribution technology using an input apparatus and a plurality of data distribution apparatuses. The input apparatus instructs a first data distribution apparatus to start data distribution (distribution start step). The first data distribution apparatus selects a data distribution apparatus that actually conducts the data distribution based on processing capacity of the first data distribution apparatus and processing load of all data distribution apparatuses (distribution apparatus selection step). For example, a second data distribution apparatus can be selected as the data distribution apparatus that actually conducts the data distribution based on the selection result. The second data distribution apparatus receives document data obtained by the input apparatus, converts the format of document data, if required, and distributes the document data (data distribution step).
However, the approaches described in JP-2002-342218-A and JP-2010-061212-A may not be effective for converting the content format into a format suitable for each client terminal and then providing the format-converted content.
For example, the conventional data distribution system described above may not be effective in the following environment. When movie content stored in a server is being projected on a screen provided with a speaker in a large conference room, audio/sound is output from the speaker. In such large conference room, a participant may be sitting at a position where he or she cannot clearly hear the audio/sound of content from his or her seat position. In such a situation, the concerned participant may connect his or her personal terminal device to the data distribution system so that the audio/sound can be received and output at his or her personal terminal device.
In this case, the user needs only audio/sound of the movie content at his or her terminal. But the conventional data distribution system may not be adapted to output only audio/sound to the concerned client terminal. Further, other than such audio/sound receiving terminal, other users may want to connect a terminal having a viewing/listening capability, or a bone-conduction earphone for hearing-impaired participants, to the data distribution system.
Further, the conventional art may not be adapted for collaborative output of content stored on a server. In such collaborative output of content, multi-media content such as movie content composed of a plurality of different types of content can be replayed as follows: one client terminal is used for outputting moving images and other client terminal is used for outputting audio/sound (i.e., separation of functions). Such collaborative output of content can devise a suitable outputting mode for a system by using a plurality of client terminals to output each type of content included one multi-media content.
Further, conventional systems may not be adapted for adding a client terminal as an output destination after replay of content has been started. For example, when the content has been replayed for some time, a user wants to connect his or her personal terminal to a system to receive and output audio/sound of the content at his or her personal terminal, but the conventional system may not be adapted for such dynamic adding of output destination.
As such, in the conventional art, only the format conversion of the entire content can be conducted for a client terminal.